#include "stdio_impl.h"
#include "pthread_impl.h"
#include <limits.h>

void __do_orphaned_stdio_locks()
{
    FILE *f;
    for (f=__pthread_self()->stdio_locks; f; f=f->next_locked)
        a_store(&f->lock, 0x40000000);
}

void __unlist_locked_file(FILE *f)
{
    if (f->lockcount) {
        if (f->next_locked) f->next_locked->prev_locked = f->prev_locked;
        if (f->prev_locked) f->prev_locked->next_locked = f->next_locked;
        else __pthread_self()->stdio_locks = f->next_locked;
    }
}

void __register_locked_file(FILE *f, pthread_t self)
{
    f->lockcount = 1;
    f->prev_locked = 0;
    f->next_locked = self->stdio_locks;
    if (f->next_locked) f->next_locked->prev_locked = f;
    self->stdio_locks = f;
}

int ftrylockfile(FILE *f)
{
    pthread_t self = __pthread_self();
    int tid = self->tid;
    int owner = f->lock;
    if ((owner & ~MAYBE_WAITERS) == tid) {
        if (f->lockcount == LONG_MAX)
            return -1;
        f->lockcount++;
        return 0;
    }
    if (owner < 0) f->lock = owner = 0;
    if (owner || a_cas(&f->lock, 0, tid))
        return -1;
    __register_locked_file(f, self);
    return 0;
}
